Free live chat porn no membership - Re os age dating
solid solution) and the parameters that control the distribution and abundances of Re and Os in molybdenite, we investigated a suite of samples from two porphyry Cu-Mo deposits, El Alacrán (Mexico).High-resolution imaging, wavelength-dispersive spectroscopy (WDS) elemental and Nano SIMS isotopic mapping provide the first view of the distribution of the Re and Os elements and their respective isotopes at the micro to nanometer scale. WDS maps for sulfur (right) and rhenium (left) in molybdenite grains.1D), whereas in sample Alacrán-B9 rhenium partitions into oscillatory zoning similar to sample Miranda 2569, with primary molybdenite depleted in Re (4,000–8,000 ppm), and secondary molybdenite enriched in the element (10,000–21,500 ppm; Supplementary Data 1).
In order to resolve the controls on the distribution of these elements, chemical and isotope mapping of Mo S grains from representative porphyry copper-molybdenum deposits were performed using electron microprobe and nano-scale secondary ion mass spectrometry.
Our results show a heterogeneous distribution of Os isotopes are not decoupled as previously thought.
We conclude that Re and Os are structurally bound or present as nanoparticles in or next to molybdenite grains, recording a complex formation history and hindering the use of microbeam techniques for Re-Os molybdenite dating.
Our study opens new avenues to explore the effects of isotope nuggeting in geochronometers.
Due to their chalcophile affinity and behavior during partial melting of the mantle, Re and Os will be concentrated in sulphide phases usually at low ppb and ppt levels, respectively. These unique characteristics explain why Re-Os molybdenite dating using the whole mineral approach is currently the most widely used single mineral geochronometer in ore deposits, where reliable crystallization ages have been obtained by the direct measurement of .
Here we investigate the distribution of Re and Os in molybdenite, the degree of isotopic and chemical zoning of these elements, the formation of Re-, Os-rich domains and particles in or next to molybdenite, and the processes responsible for intracrystalline/intragrain fractionation. Carlson for comments that improved our presentation. Peucker-Ehrenbrink for making accessible his Os data set.Os isotopes in molybdenite is critical in interpreting isotopic measurements because it can compromise the accurate determination and interpretation of mineralization ages.Direct observation of (i) oscillatory isotopic and chemical nano-zoning of rhenium, (ii) Re-rich overgrowths, and (iii) presence of common Os in domains in molybdenite grains and in the associated nanoparticles provide an explanation for spurious Re-Os ages obtained by laser ablation ICP-MS.Alternating incorporation of Re into molybdenite during growth (Fig.Rhenium in molybdenite from El Alacrán has a bimodal distribution.Tags: Adult Dating, affair dating, sex dating